Safety joint bumper sub



J. E. REED i SAFETY. JOINT BUMPER SUB Fiied Aug. 5, 1941 Feb. z, 1943.

' v-wf Patented Feb. 2, 1943 UNiTElD STATES l'PAT-ENT OFFICE SAFETY JOINT BUMPER SUB John E. Reed, Bakersfield, Calif.

Application August 5, 1941, Serial No. 405,506

(Cl. Z55-27) 1 Claim.

This invention is an assembly constituting a sub and safety joint for 'use in a given string of deep well apparatus, such as drill stems or drill pipe.

It is an object of the invention to provide ay An object is to provide an extremely simple and substantial and reliable safety joint of lfew El' and low-cost parts, and to provide a safety joint of efcient connecting function and very easy operating capacity in making and breaking the joint; that is, disconnection of thev parts without damage in any degree.

It is an object of the invention to provide a safety joint which will have capacity to perform as a substitute for a jar tool to a considerable degree and will eliminate use of automatic spring or other controlled snap or trip devices to effect a bump of one part on another, and will utilize kinetic energy of the heavy moving string portions to impart a hammer impact up or down as to a struck lower portion of a well apparatus string.

An object is to provide a safety joint of' such construction, combination and functions that the two portions of the string can, in one function be securely locked for co-rotation and lift and lower, in another function for relatively free, limited and considerable jar stroke of the upper string portion as to a lower string portion, and in a still further function to provide for a simple unhitch of the string portions so that the upper portion can be hoisted away from a stuck lower part attached to a member of the safety joint.

It is particularly an object of the invention to provide a safety joint which is entirely free of shear-off features and of screw thread connections as between the safety hitch members which, however, do have conventional threads for pin or pin-box parts of a string on which the safety joint is to be connected at any desired position in the string length, and at the same time provide a joint of maximum strength and simplicity of action because of elimination of shear pins and threads as between the essential members of the joint.

An objection to shearing devices in joints of this type is that there is always a degree of uncertainty `of 'the shear factor, and because the parts will'shear at a tension less than that which may readily effect an extraction of a frozen or jammed tool'string instrument. By the present invention joint members are positively interlocked for rotarydrive, for pull and for lowering by integral'element features of no shearing function and which can be uncoupled at any time without a previous shear function; which can bejoint-'opened `for relative reciprocation and then re-locked at will, and can be entirely unhitched for retraction of one joint member as to another without any shear and without any unscrewing operation and the joint can be again re-hitched if desired to the part still left in the hole or well.

4A further object is to provide for both a right hand and a left hand rotation of the lower string portion'hy way of the joint.

The 'invention consists in certain. advancements in the art of Vdeep well apparatus a's set 'forthin the ensuing `disclosure and having, with the above, additional-objects and advantages as hereinafter developed, vand whoseconstruction, combinations and details of means, and the vmannerof operation will be made manifest in Athe description'of the herein illustrative embodiment; it being understood that alterations,

Vvariations and modifications may be resorted to within theiscopegprinciple and spirit of the invention as it is more particularly claimed presently.

lFigure lis a partly'sectional, longitudinal elevation of the locked-up joint assembly ready for screw attachment to upper and lower string portions (shown dotted).

Figure 2 is a sectional View showing the joint members in unlocked, limited stroke, jar function position.

Figure 3 is a section showing the members in a full unlocking-function position.

Figure 4 is a cross-section on line --l of Fig. 3.

The joint includes a barrel member 2 whose upper end has pipe threads 3 for an elongated sleeve 4 whose top has a pin-box 5 to thread onto the upper portion of a well string of any desired combination. The upper end of the barrel 2 has a stufling gland 6 which is packed on a possibly reciprocative wash pipe l fixed, for instance to another element in the assembly.

Here the wash pipe 'l is rigid with the upper end of a co-axial hollow mandrel l0 whose periphery slidably fits in the bore of the barrel 2 and includes a body I l having a tool joint pin I2 or other device for attaching to the subjacent portion of a given apparatus string.

The barrel member and the mandrel member are provided with means preferably integral or self-contained so as to each to effect a reliable hitch of one to the other and the readily unhitch and limited relative reciprocation for jar function, and for total, easy uncouple.

For these purposes one of the members, here the mandrel I0, is provided with one or more Y-slots (one only being here shown for clarity) including a long Way I3 having a lateral recess I3 at its foot and at the upper and opposite side is a side pass I4 well below the upper end of the way I3. From the pass I4 there extends a mouth I5 outletting at the top of the mandrel III; the top and the bottom of the way I3 being blind.

The companion member, here the barrel 2, has one or more pairs of lugs (one pair for each Y- slot) B, at the bottom of the way I3, and T, at the upper part of the way, and which lugs, of a pair, are so angularly disposedv that bottom lug B will register in the recess I3' Whilst the upper lug T is in the cross pass I4, as in Fig. 1.

These lugs 4.are slightly shorter than the recess I3 and the pass I4 and are adapted to readily turn laterally into the recess and the way and the bottom lug B will engage the near, side wall of the recess I 3 and thus stop further right hand rotation (looking down) of the lbarrel about the mandrel and thereby co-rotation of the joint members is made positive. The upper ends of the lugs B and T are suitably bevelled at I6 to aid in register of the lugs in their recess and pass places in the Y-slot.

The-way I3 is wide enough to slidably receive the lug B when the barrel 2 is rotated to the left (looking down) and the barrel is pulled upward whilst the mandrel is stationary, as when held by a stuck tool on the lower string portion. Also the mouth I5 slidably receives the lug T at the time the lug B is in the way I3.

y It will now be clear that if the barrel is elevated, Fig. 2, the unlocked lug B will slide up in the way I3 until the lug impinges on the head wall I3a of the way I3. Thus upstroke of the barrel lug B, if gradual and steady, may suflice to eventually put enough strain on the mandrel by way of the head wall I3a to drag loose the stuck lower portion of the tool or other string. Or hammering jars may be imparted by the barrel lug B to the mandrel by utilization of kinetic energy of the upper string and the attached barrel if these be sharply jerked upwardly under the control of a skilled driller or operator.

A down jar may be achieved if the upper string portion and the barrel 2 be allowed to fall the distance from the foot end of the barrel to its landing shoulder I Ib of the body I'I.

During such periods that the driving and hammer lug B is Working in the blind way I3 (without unhitch of the barrel from the mandrel) the secondary or auxiliary lift lug T is working in or from and into the open end of the mouth I5 of the Y-slot.

If Vit is desired to entirely unhitch the barrel member 2 from the mandrel III it is only necessary to turn the barrel lug B through the pass I4 and up and out of the throat I5; the upper lug T being already out of the throat and above the top of the mandrel. Hence the barrel 2 is now entirely free of the mandrel presumed to be held by the frozen tool in the well or hole.

Therefore, complete unhitch of the joint can be made at any time by a slight left hand turn of the upper string portion and the Ibarrel 2 to work the lug or lugs B and T upand out of the Y-slot in the mandrel without putting a dangerous left torque on the string and that might open the string at any of the usual screw joints of its sections.

The chamber of the barrel in which the mandrel Works is at all times protected against fouling solids that could sand up the barrel and Y- slot. The drive lug B has no jamming interlock in the recess I3 and can be freely turned to the left without undue resistance to eect an opening of hitch parts between the joint members 2 and Il).

What is claimed is: y

A bumper sub of the class described and comprising an exterior sleeve having a pair of longitudinally spaced, inwardly extending off-set, upper and lower lugs, and an inner mandrel slidable and turnable in the sleeve and having an elongate way for the lower of said lugs and havingV a passing-out slot extending from the Way arranged so that both of said lugs may pass therethrough in sequential steps; the mandrel having an exterior, annular shoulder opposite to and arranged to coact with the end of said sleeve the lower lug having an inclined surface which may be wedged with the inclined surface of a notch extending from said elongated Way, the wedging being brought into effect by relative rotation of the sleeve and the mandrel, and the meeting of the end of the sleeve and the shoulder.

JOHN E. REED. 

